Rotation on meridian flip
Posted: Tue Sep 01, 2020 5:58 pm
On a recent image image, I noticed considerable (5+ degrees) rotation between images taken before and after the meridian flip. Ordinarily, I would just crop off the edges and not worry about it. But there was a bright star in the field, and the diffraction spikes from the before and after frames didn't line up.
I know that the rotation indicates that something is not perpendicular to something else, but I am having trouble visualizing what. Before I give myself a headache, I thought I'd ask if anyone else has tracked down and fixed a similar problem.
For reference, it is an iOptron CEM-60. I recently re-balanced everything, and am happy with tracking, guiding, etc. The scope is a 200mm Newtonian, mounted with the focuser and camera down, in the zero position.
I know that the rotation indicates that something is not perpendicular to something else, but I am having trouble visualizing what. Before I give myself a headache, I thought I'd ask if anyone else has tracked down and fixed a similar problem.
For reference, it is an iOptron CEM-60. I recently re-balanced everything, and am happy with tracking, guiding, etc. The scope is a 200mm Newtonian, mounted with the focuser and camera down, in the zero position.